In dental technology, dental procedures may include gingival retraction in which a space is opened surrounding a preparation margin. Adequate retraction must be accomplished in all subgingival areas to guarantee that a dental impression material or digital scan registers at least the preparation margin. Different methods of gingival retraction may include the use of retraction cords, laser or electrosurgery, or retraction paste. During a retraction procedure with a retraction paste, the paste is dispensed or injected into the gingival sulcus. After a predetermined time, the paste is removed leaving a clean, dry and visible preparation margin. Once removed, the clinician may proceed with the impression or scan.
Dental procedures may also include restoration procedures. In this regard, the clinician may remove a defect, such as dead tissue, and then fill the cavity produced by removal of the defect with a filler material. Typically, curable materials are used to produce the filling. In this case, the filler material is placed in the cavity as a paste or liquid. Once the material cures, the filling seals the cavity. There are different types of fillings.
One type of filling is a direct restoration in which the filler material completely fills the cavity. Another type of filling is an indirect restoration in which a customized component, such as an inlay, is fabricated outside of the patient's mouth and is then inserted into the cavity. A filler material, for example, a dental cement, bonds the customized component with the wall of the cavity. The filler material mechanically anchors the component in the cavity, but also seals the cavity. In either case, the filling must not include gaps through which contaminants and germs may penetrate to potentially destroy the filling and damage the underlying tissue.
To that end, dispensing of the filler material into the cavity is particularly important to the successful formation of the filling. In the dental industry, a dental instrument may be used to dispense the filler material. The structural size and mechanical aspects of the instrument play a significant role in successfully dispensing the filler material into the cavity. The dental instrument may include a handpiece and a nozzle through which the filler material is dispensed into the cavity.
The handpiece may generate mechanical vibrations, such as, ultrasound, which may facilitate dispensing of the filler material through a nozzle. A combination of ultrasound and pressure make it possible to use filler masses with a relatively high content of fillers. These types of fillers may be preferred because of their relatively high toughness and resistance to shrinkage and to gap formation upon curing.
The nozzle may include a cartridge having a pre-selected formulation of filler material. The clinician may select a cartridge of or a nozzle containing a particular filler material for use. The nozzle/cartridge is secured to the handpiece in a manner that transmits the energy from the handpiece to the filler material. Upon actuation of the handpiece, the filler mass is dispensed from the nozzle into the cavity. Once dispensed, the filler material may return to a non-slumping, sculptureable state such that, before the filler material cures, the clinician may carve the filler material to match the patient's remaining anatomy.
While dental instruments and cartridges of specific formulations of filler material have been generally successful, manufacturers of such cartridges continually strive to improve their use and functionality. In this regard, there remains a need for broad cross application between handpieces and commercially available compules.